Browsing by Author "Choudhuri, Chandrani"
Now showing 1 - 3 of 3
- Results Per Page
- Sort Options
Item Open Access Antifungal Efficacy of Cu-Based Nano-Chitosan on Rhizopus stolonifer, A Virulent Phytopathogen(University of North Bengal, 2022) Chouhan, Divya; Choudhuri, Chandrani; Dutta, Poulami; Mandal, Palash; Mathur, PiyushAgro-scientists are giving endless efforts for synthesizing a bio-derived molecule that can act as a promising antifungal agent for combating a large number of phytopathogens. Harmful phytopathogens decrease crop yield and its quality. Rhizopus stolonifer is one such virulent phytopathogen that causes huge losses during the post-harvest period of crops. This pathogen mainly causes rot disease in fruits, crops, and vegetables. The second most abundantly available biological macromolecule, Chitosan and its metal-based nanoparticles stands as a potential antifungal agent for combating Rhizopus stolonifer. This study includes the synthesis of Cu chitosan nanoparticles (Cu-CNPs) and chitosan nanoparticles (CNPs) through the ionic gelation method and its characterization based on UV Vis spectrophotometer, FE-SEM, EDXS, and DLS. Cu-CNPs and CNPs were screened from 100-2000 µg/mL concentration against R. stolonifer for the assessment of its antifungal activity. Spore viability assay and lipid peroxidation of the pathogen using Cu-CNPs and CNPs were also determined. Generation of oxidative stress in the mycelium of the pathogen on the application of Cu-CNPs and CNPs was traced by fluorescence microscopy. Changes in the ultra-structure of the sporangium of R. stolonifer after treatment with Cu-CNPs and CNPs were visualized under SEM. Results showed that Cu-CNPs inhibit the growth of R. stolonifer at 2000 µg/mL and elevate malonaldehyde (MDA) content in the pathogen as a result of lipid peroxidation and produces defined damages on the sporangium membrane as observed under electron microscope. Fluorescence microscopy revealed the emission of high intensity of fluorescence due to the generation of oxidative stress in Cu-CNPs treated fungal mycelium.Item Open Access Influence of culture media and environmental factors on mycelial growth and sporulation of Alternaria alternata (Fr.) Keissler causing leaf blight disease of niger (Guizotia abyssinica (L.f.) cass)(University of North Bengal, 2015-03) Saha, Aniruddha; Choudhuri, Chandrani; Saha, DipanwitaAlternaria altermata is isolated from naturally infected niger leaf for their morphological characteristics, mycelia growth and sporulation, spore germination in different culture media and environmental conditions. RMA was best for both growth and sporulation. Excellent sporulation was observed ion PCA. PDB supported best growth among the liquid media tested. Highest mycelia dry weight was recorded at 28°C and pH 6.5. Among several carbon sources tested, Mannitol showed optimum growth and sporulation while peptone produced maximum growth among the tested organic nitrogen sources. The present study will help to maintain the fungus in the laboratory condition for preparation of inoculums for different studies related to the control measures of the pathogen.Item Open Access Studies on the resistance of niger [Guizotia abyssinica (L. F.) cass.] against alternaria alternata causing leaf blight and control of the disease using botanicals and antagonists(University of North Bengal, 2009) Choudhuri, Chandrani; Saha, Aniruddha